00:01
So if you look in the text, figure four shows us exactly what we're looking for.
00:07
In part a, we have a monopolistically competitive firm.
00:12
There's the demand, marginal revenue, marginal cost, and average total cost curves.
00:18
So everything there is what we need.
00:21
All we need to do is just reproduce that diagram exactly as it is.
00:25
So this is going to show the market for sparkles toothpaste.
00:32
Okay.
00:33
The first thing we need to find here is the profit maximizing output and price.
00:39
Well, we know firms always want to produce where marginal revenue equals marginal cost.
00:43
So that's here.
00:45
Quantity produced.
00:48
Normally, marginal revenue equals demand, but for the monopolistically competitive firm, that's not the case.
00:53
Instead, demand is greater than marginal revenue.
00:58
So instead of the price being marginal cost here, instead the prices here at p.
01:06
The difference between those two being the markup.
01:10
Okay.
01:10
Now, what is sparkle's profit? sparkle's profit is going to be that markup times the quantity produced.
01:23
In other words, their profit is equal to the markup.
01:26
Up on each unit times all of the units that are sold.
01:33
Now, we need to show the consumer surplus that we actually get from purchasing sparkle toothpaste.
01:41
Okay, so let's zoom in real quick, just to make this a little clearer.
01:46
Consumer surplus is always bounded at the bottom by price and bounded on the right by the demand curve.
01:57
We'll just extend the demand curve all the way to the vertical...